Compound roofing-sheet.



PATENTED APR. 23, 1907.

-H. R. WARDELL.

COMPOUND ROOPING SHEET.

APPLIOATION FILED JAN. 23, 1906.

INVENTOR.'

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HENRY R. WARDELL, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE BARBER ASPHALT PAVING COMPANY, OF PHILADELPHIA, PENN- SYLVANIA, A CORPORATION OF WEST VIRGINIA.

Specification of Letters Patent.

` Patented April 23, 1907.-

Application filed January 23, 1906. Serial No. 297,418.

T all whom/ t ntwy concern:

Be it known that I, HENRY ItWARDELL, residing at Hamilton Court, in the city and county of Philadelphia and State of Pennsyl- Vania, have invented certain new and useful Improvements in Compound Roofing-Sheets, ofwhich the following is a specification, reference being had to the accompanying drawings.

lo My improvementsrelate to composite bituminous roofing sheets of which the basis consists of textile or felted organic fabric in combination with bituminous layers which serve the double function of protecting and i 5 strengthening the fabric.

As heretofore manufactured, the basis of such sheets has usually consisted either of coarse paper or what is known as woollfelt or other coarse felted material, saturated with 2o a bituminous preservative solution, usually liuid solution of asphalt in oil, and in this respectmy present invention does not differ from the prior art. It has also been heretofore customary to coat the surface of the fabric which forms thebasis of the roofing sheet with a thick vasphaltic solution, the purpose of which is both to protect and to strengthen the foundation fabric.

The protection of the fabric is two fold, 3o first, to prevent rain or moisture from penetrating it, causing rotting or decay and second, to prevent the sun or the atmosphere from effecting volatilization of the oily ingredients of the saturating compound which 3 5 `permeates the fabric. It will be understood ,that when; in this specification, I speak of-a protecting layer, of bituminous compound, I refer to a layer devised expressly so as to eifectythis two fold protection. The 4o strengthening ellect of a bituminous layer so equally necessary, but entirely distinct from its protective character. In themselves, such fabrics as are used for roofing purposes, do not possess su'llicient consistency.

Paper or felt is very easily torn and possesses little strength 3 burlap is tougherbut is flimsy, being liable .to be distorted by slight strains. A properly applied bituminous layer confers upon-the fabric which forms the basis of the roofing, that stiffening and strengthening effect which is required to make it an ell'ective roofing material, strong enough to withstand the ordinary strains and wear to which such material is subjected, without tearing or distortion. 5 5

Heretoforc, no distinction has been made between the use of a bituminous layer to confer protection, and its use to confer strength', and accordingly, previous material of this character has` been unsatisfactory in this re- 6o spect. The diiliculty relates to the proper consistency andromposition to be given to the layer, and .results from the impossibility of making a single substance properly perform these two functions for, if an asphaltic layer be made of a sufliciently hard consistency to effectually exclude moisture and protect the enclosed oily constituents, it is too brittle to give to the sheet the desired strength while on the other hand, if it be .7 made soft enough to confer strength and toughness, it fails in its function of properly protecting the fabric. Recognizing these ditliculties in the way of obtaining from one layer, or from several layers they be of the 7 5 same nature, the combined protective and strengthening efl'ect which is desired, my invention consists in providinga roofing sheet with two or more layers having different characteristics, the outside layer or layers being specially designed for the purposes of protection, and the inside layer or layers being especially designed for the .purpose of strengthening the sheet.

It is obvious that this invention is capable 8'5 of variation in its application, and that it 'may be employed in connection with a great variety of compound bituminous roofing sheets. I will however, describe my invention as applied to certain forms of sheet which I consider desirable, by way of exemplification of the invention, with the understanding that my invention is not limited to the specific forms which I will now proceed to describe.

In the accompanying drawings, Figure I, shows in perspective, and Fig. I, in transverse section, a simple application of my invention to a compound sheet built up with two layers of a felted fabric such as wool felt. Figs. III, and IV, similarly show thc application of my invention to a composite sheet of which both a felted fabric and a woven fabric such as burlap are used as the basis of the sheet, and in which the external .protective asphaltic layer is made thicker on one side .IOCI

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Y vthan the other, and provided'with a protect; ing layer of` grit or .sand as a safe guard i, and n.

The basis ofthe sheet consists of the two layers, l, and 2, of felted fabric. This may be anyof, the known formsof roofing paper or roofing felt, butl prefer to employ wool'gfelt. This vfelt is thoroughly saturated by an asphaltic compound; the saturating compound is prepared by using a natural asphalt, ora mixture of two or more' such natural asphalts, thoroughly fluXed by the addition of an goil, such as a petroleum residuum which 'is commercially known as maltha. Sufficient of the flux must be'added to produce a compound which, at the comparatively high temperature at which the satura-v tion takes place, approaches the fluidity of water, for only thus can complete'saturation of the felted fabric be secured. This saturating com ound adds to the strength of the felted fa ric, which prior to asaturation has little strength. It also tends to preserve the felted material; but it must also be understood that such a saturated fabric unless further protected,'cannot long resist the destructive effects of moisture and theatmosphere, because of the rapid drying out of its oily constituents withthe consequent elimination of both the strengthening and the protective effect of the .saturating compound. Tn order therefore to make an eHective comi osite roong sheet it isnecessary to comine these saturated fabrics with distinct layers of bituminous composition to afford additional protection and strength; and for this purpose, I prepare two different sorts of asphaltic compositions, one specially designed to afford protection, and `the other especially designed to afford strength.

The strengthening layer is composed of an asphalt which for this purpose should preferably be chosen to containa considerable proportion of mineral matter, such for example,

l as Trinidad asphalt, as the presence of a f'ss " pared.

proper quantity of such mineral matter tends toincrease the strength of the `asphaltic laver. This asphalt is then fluXed by the addition of the proper Aquantity ofan oil such as maltha, untill a penetrationl is attained of preferably from 60 tov80 on the Bowen penetration machine at 78 Fahrenheit.A

lThe protective layer isdifferently pre- Instead of an asphalt containing mineral matter, there is used an asphalt as pure as possible, and one with a high melting and a low congealing point. This is fluxed, as with maltha, until it exhibits a penetra'- tion of preferably from 25 to 55o on the illowen penetration machine at 7 8O Fahreneit.

Between felt sheets l, and 2, there is irn terposed a layer 3, of the strengthening asphalt composition, the pre aration of which T have described. Upon oth of the outer surfaces of the compound sheet thus formed, there are applied layers 4,.and 5, of the protective asphaltic .composition prepared as l have explained.

It will be understood that a roofing sheet thus built up has much greater durability than other previous forms, The outer layers of the asphalt composition are especially designed to thoroughly protect the softer interior parts, and are hard enough and resisting enough to effectually prevent the penetration of moisture from without or the volatilization of the preservative oils from. within. On the other hand, in addition to the strength thus imparted to the fabrics which form the sheet, the intermediate layer 3, of the strengthening a'sphaltic composi tion, is peculiarly adapted to add strength and toughness to the compcsite'sheet. this layer, effectually protected as it is from the volatilizing effects of the' atmosphere, is formed. vof an asphaltic composition which imparts great strength and which does not tend to become brittle.

It is obvious that, without departing from the spirit of my invention, more than two of the felt sheets may be employed, and in such case it is best to interp`osea layer of the For strengthening asphaltic composition between tuted for one of said sheets, a sheet 'of burlap.

In the drawings, l0, .represents the felt sheet and 11, the sheet of burlap. Between these two layers there is interposed a layer 12, of a strengthening asphalric composition prepared as -I have already described. 'On the external surface of the composite sheet thus formed, there are applied layers of the protective asphaltic composition. Of these, the lower layer 13, which comes in contact with the boards of the roof which is to be protected, need not be applied very thickly; but the upper layer 14, ismade. much thicker, and for this purpose it is desirable to have the burlap overlie the felt because burlap will support a thicker layer of an asphaltic composition than will felt. To this upper layer there may be applied a coating of sand or grit 15, which tends to prevent the destructive effect of falling cinders or embers which, if they come in direct-contact with the upper protective layer may melt it, and make ahole through which water may thereafter penetrate. i K Having thus described my invention, l claim l. A composite roofing sheet provided with layers of bituminous composition of TOO IIO

Aditfering physical characteristics, including an external layer having high protective characteristics, and an internal layer having high strengthening characteristics, substantially as set forth. t

2. A composite roong sheet formed upon a'basis of two' or more. organic fabrics satu rated with a bituminous compound, and having. interposed between them a layer of bituminous composition, having high strengthening characteristics, and having applied to the external surfaces of the composite sheet layers of bituminous composition having high protective characteristics, substanti ally vas set forth.

8. A'composite rooting sheet formed upon -a basis of organic fabrics saturated with an asphaltic composition; having interposed between them an asphaltic layer of about'the 2o consistency described for strengthening purening characteristics, interposed between said fabrics; and a layer of bituminous composition, having high protective characteristics, upon each of the outer faces of said fabrics, substantially as setjforth.

In testimony' whereof, I have hereunto signed my name, at Philadelphia, Pennsylvania, this 20th 4day of January 1906.

HENRY R. WARDELL.

Witnesses JAMES H. BELL, E. L. FULLERTON. 

